Finding the Fourth Proportional to 2,085.81, 2,878.74 and 1,189.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.81 : 2,878.74 = 1,189.55 : x
2. Step 2: Convert to fraction form
   2,085.81/2,878.74 = 1,189.55/x
3. Step 3: Cross multiply
   2,085.81x = 2,878.74 × 1,189.55
4. Step 4: Simplify right side
   2,085.81x = 3,424,412.36
5. Step 5: Solve for x
   x = 3,424,412.36/2,085.81
6. Step 6: Final answer
   x = 1,641.77